fix: reuse existing node user (uid 1000) in Dockerfile

Dockerfile

@@ -16,18 +16,16 @@ FROM node:20-alpine AS runner
 
 WORKDIR /app
 
-# Hugging Face Spaces runs containers as uid 1000
-RUN addgroup -g 1000 appgroup && \
-    adduser -u 1000 -G appgroup -s /bin/sh -D appuser && \
-    mkdir -p /data && \
-    chown -R appuser:appgroup /data /app
+# node:20-alpine already has a 'node' user with uid 1000 / gid 1000
+# HF Spaces runs containers as uid 1000 – so we reuse the existing user
+RUN mkdir -p /data && chown -R node:node /data /app
 
-COPY --from=builder --chown=appuser:appgroup /app/package.json /app/package-lock.json* ./
+COPY --from=builder --chown=node:node /app/package.json /app/package-lock.json* ./
 RUN npm ci --omit=dev --ignore-scripts
 
-COPY --from=builder --chown=appuser:appgroup /app/dist/ ./dist/
+COPY --from=builder --chown=node:node /app/dist/ ./dist/
 
-USER appuser
+USER node
 
 # Hugging Face Spaces default port
 ENV PORT=7860